Another GWAS meta-analysis that suggests replications when the opposite is the case

"Since the discovery of general cognitive ability (or ‘g’) in 1904..."  (When I read a sentence like this, I am already a bit leery of what will come next.)

This critique is for the following study: 

Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function.  Gail Davies, et al.

This study is a meta-analysis of several studies I have already critiqued, here, here and here, as well as some new cohorts.  If I understand correctly, the new ones are the CHARGE and COGENT cohorts, but  in any case, it does not appear that any of the new datasets were ever studied independently related to cognitive ability and were simply added to the N of the meta-analyis.  I have a problem with this, which hopefully will become obvious as you read this critique.